small amount of protein, enough to support
the browning reactions that generate typical
roasted flavors (p. 778) at moderately hot
temperatures. Evergreens such as pine, fir,
and spruce also contain significant amounts of
resin, a mixture of compounds related to fats
that produce a harsh soot when burned.
How Burning Transforms Wood into
Flavor Burning temperatures transform each
of the wood components into a characteristic
group of compounds (see box, p.449). The
sugars in cellulose and hemicellulose break
apart into many of the same molecules found
in caramel, with sweet, fruity, flowery, bready
aromas. And the interlocked phenolic rings of
lignin break apart from each other into a host
of smaller, volatile phenolics and other
fragments, which have the specific aromas of
vanilla and clove as well as a generic
spiciness, sweetness, and pungency. Cooks get
these volatiles into solid foods, usually meats